Primary Amelanotic Malignant Melanoma of the Tongue.

Primary malignant melanoma rarely occurs in the oral cavity. The tongue is a particularly unusual primary site; lesions may be pigmented or amelanotic. Primary malignant melanoma is frequently mistaken for squamous cell carcinoma. A 27-year-old male presented with a large, painless, ulceroproliferative mass on the dorsal surface of the tongue for 6 months. Squamous cell carcinoma was suspected, and the lesion was biopsied. Histopathology was compatible with primary amelanotic malignant melanoma. The patient had no cutaneous lesions consistent with malignant melanoma, and no definitive metastatic lesions were found. Ultrasound and computed tomography did not reveal any evidence of regional draining lymph node metastasis or suspicious lesions anywhere else in the body. The patient underwent composite resection of the tongue tumor and bilateral neck lymph node dissection, had an uneventful postoperative recovery, but was lost to follow-up. Primary oral amelanotic malignant melanoma is a highly aggressive, potentially fatal tumor and because of its rarity, presents a diagnostic challenge. The ideal treatment modality for primary malignant melanoma of the tongue is poorly defined, but surgery is regarded as the most effective course of therapy.